Underground tunnel work on the renewable energy project was halted after an industrial ventilation fan malfunctioned and caused metal shrapnel to fly through the air.

In a separate incident, a crane abruptly malfunctioned during work.

SafeWork NSW inspectors attended the site and issued six prohibition notices to cease the use of the unsafe fans.

SafeWork NSW acting Deputy Secretary Trent Curtin said the safety risks were “unacceptable”.

“We have been on site this week speaking with management, health and safety representatives and workers, and unfortunately received reports of two dangerous incidents on the weekend and Tuesday which are seriously concerning to me,” Curtin said.

“I’m advised one incident involved a crane malfunctioning, while another incident involved a ventilation fan failing with metal debris flying out from the fan. 

“Our investigation led us to discover that other fans were also at risk. These are significant safety events and it is lucky that no one was hurt.”

Australian Workers Union NSW Branch Secretary Tony Callinan said the fan “catastrophically malfunctioned” and that it was by “sheer fortune” nobody was injured.

”This latest incident represents a significant near-miss that could have resulted in workers being killed,” Callinan said.

“Had anyone been in the path of this high-velocity shrapnel, we would be discussing fatalities rather than equipment failure.”

There will be an independent safety review following the incident and all underground workers have been temporarily pulled off the job.

“Every worker deserves to go to work knowing they are in a safe environment from which they can expect to return home every day,” Curtin added.

“SafeWork NSW Inspectors have prohibited the use of unsafe ventilation fans until they can be satisfied that they will be operated in a safe condition,” Curtin added.

“We will always work to ensure that every worker gets back home safely every day.”

The driver was working on part of the company’s Snowy 2.0 project, which involves building an underground Hydro power station, linking the Tantangara and Talbingo dams.

His truck crashed and rolled on the Snowy Mountains Highway, trapping him inside the vehicle. He did not survive the crash.

Construction on Snowy Hydro 2.0 began in 2019.

Former prime minister Malcolm Turnbull announced the project in 2017, describing it as an “electricity game-changer”.